The studies proposed and under investigation involve the development of protocols for synthesis of a variety of complex natural products with a broad spectrum of biological activity. The methodology under development includes application of the internal Diels-Alder reaction to the construction of the marasmate skeleton, and the amaryllidacea alkaloid lycorine. Also development of the chemistry of vinyl ether anions will be undertaken including applications to the prostaglandins and other naturally occurring systems including the ionophone calcimycin (A-23187). Finally, the use of cross cnjugated enolate systems and conjugate addition-annellation in approaches to the sesterterpenes, particularly the ophiobolin/ceroplastol class will be investigated. It is expected that these studies will lead to the preparation of potentially valuable analog systems for biological screening.